A rail-mounted, wheel-sensing system is shown having a wheel sensor and a rail mounting platform. The system includes a rugged steel rail clamp including two blocks mounted on the base of the rail by a pair of bolt extending under the rail. One block is connected to a vertically adjustable mounting bracket for carrying a sensor or other device. The mounting bracket includes a platform for the sensor. Two shields on the platform protecting a sensor mounted between them. An adapter plate may be added between the mounting bracket and the clamp for installation on lighter or heavier rails.